Nutritive Value of Keratin

Abstract

Finely powdered keratins have been studied as possible protein sources for growing rats and chicks. When chicks or rats were fed purified rations which contained 30–40% of powdered hoofs, substantial growth was obtained. High levels of powdered hog hair in chick rations allowed moderate growth but usually produced an encephalomalacia unless sources of vitamin E were present. Powdered chicken feathers allowed only poor growth. In general, the rates of growth obtained with chicks and rats fed rations containing these keratins show a positive correlation with the degree of subdivision of the keratin. The use of a ball mill for grinding the keratin was not as effective a method as one in which heating was prevented. When the lower levels of powdered hoofs were supplemented with lysine, tryptophane, methionine, and histidine, good growth was obtained.